Process of hair waving and preparation therefor



2,990,336 PROCE$ OF HAIR WAVING PREPARATION THEREFOR Harry Martin, Monroe, N.Y., asdgnor, by direct and mesne assignments, to Permanent Hair Waving Corporauon, Norfolk, Va., a corporation of V No Drawing. Filed Oct. 16, 1959, Ser. No. 846,818

9 Claims. (Cl. 167-871) now Patent No. 2,773,293. This application is a continuation-in-part of my application Serial No. 326,593, filed December 17, 1952, now abandoned, that is, in turn a continuation-in-part of my application Serial No. 437,

628, filed April 4, 1942, and the subject matter of the latter application is included in my application Serial No. 255,725, filed November 9, 1951. All of these preparations which have been found commercially feasible are supplied on the open market for hair waving in solutions in which a water medium is supplied, adjusted to a predetermined hydrogen ion concentration of pH, which is calculated to minimize damage of toe hair, or to stabilize the product in accordance with the use to be made in the hands of a professional hair technician or chemist.

In accordance with my discovery, these products are subject to objection by reason of the prescription to wash the hair before the application of the cold waving preparation and afterward. While this procedure may seem to be innocuous, it has been my experience that lack of attention to the nature of the diluting agent, rinsing agent or washing agent has resulted in damage to the hair, and has made for unpredictable results, especially in the hands of the unskilled. This I attribute to the fact that in the useof hard water, such as is found in various portions of the world, including various mid-western and western states of the United States, there is a sutlicient presence of calcium compounds and the alkaline earth compounds, such as magnesium or lime, to combine with the thioglycolic acid radical or various mercaptans to form undesirable reactions, even to the point of forming a depilation component. This latter reaction product is especially harmful to the, hair it the hair waving solution is permitted to dry on the hair or stay in contact with the hair for long periods, such as overnight, in which event there occurs at least a superficial concentration of the calcium in combination with the mercaptan employed, to form a depilation compound, dulling or weakening the hair.

In accordance with. one form of my invention, I have found that if the solvent for the water soluble mercaptan compounds is brought together with these mercaptan compounds on the hair under conditions minimizing, if not completely excluding, the presence of minerals found in hard water, such as the alkaline earth materials, of which magnesium and lime are examples, and under conditions minimizing the presence of adsorbed air or oxygen, that standard procedure may be adapted for hair waving, particularly in the cold,-to secure highly desirable hair waving operations with minimum hair dulling effects, and thereby to secure a standardized time factor in the exposure of the hair to the hair waving mixture.

More specifically, in accordance with my invention, I have discovered that hair waving, particularly in the cold, may be carried out with controlled time factors and without harmful effects, and more particularly without initially rinsing or washing the hair, by the procedural Patented June 27, 196i 2 step of employing the hair waving components comprising water soluble mercaptans in carbon dioxide generating solutions, such as carbonic acid water whereby introduction of harmful minerals in the hair waving preparation is minimized and the introduction of oxidizing components retarded, if not completely eliminated.

Still more particularly it is contemplated by my in vention to provide a hair waving preparation which is self contained in the relationship of the mercaptan radical to the base, which may be stored under any climatic conditions without deterioration so as not to require special packaging prescriptions but which is arranged to be brought into solution in an aqueous medium when required by the addition of the aqueous solvent, whereby the formation of the undesirable by-products and obnoxious (M1018 is minimized, if not completely avoided, and upon solution in the carbonated aqueous medium, assures a standardized stren without the introduction of components which may deleteriously affect the hair in the process of conducting the hair waving operation, whether in the cold or by associated application of external heat.

Still further, in accordance with my invention, I have discovered that novel mechanical as well as chemical procedural benefits are obtained in cold hair waving by directly applying a cold hair waving preparation of water soluble mercaptan compounds dissolved in a carbonic acid releasing solution, such as carbonic acid solutions, and applying the solution so made to the hair, whereby initial rinsing or washing of the hair may be avoided, a predetermined strength of mercaptan is applied and an inter-facial agitation secured between the solution and the hair to cause an efiicient hair waving operation in which the curl which results is efiected in the wet and persists after drying with highly desirable results, evidencing little or no dulling or embrittlement of the hair when dry.

Still more particularly it is an object of my invention to provide ahair waving preparation which is selfoontained with regard tothe relationship of the acidic factor to the base factor, to cause a relaxation of the hair component, to produce a highly desirable wave which persists in the transitory stage from a wet curl to a dry curl, and has predetermined strength by reason of its in activity when stored dry, characterized by its predetermined strength when it is employed to wet the hair in the procedure for carrying out cold waving operations in the presence of water charged with carbonic acid gas and furthercharacterized by exerting inter-facial agitation on contact with the hair whereby initial rinsing or washing operations are omitted and deleterious side ef-. fects overcome. I

Further novel inherent aspects of my preparation and the process of producing hair waving will become apparent and be more clearly outlined as this description proceeds.

For a clearer understanding of my invention, I refer to the following:

Example I.Preparation of dry ammonium thioglyeolate hair waving preparation.

Thioglycolic acid is dissolved into chilled isopropyl ether. Into this solution maintained at a temperature below about 37 F. there is then introduced ammonia gas by bubbling the same into it. Additions of the ammonia" gas are charged into the ether solution of thioglycolic acid, in accordance with the alkalinity of the end product which is desired.

Desirably the introduction of the ammonia gas may be the point where the separated ammonium thioglycolate evidences pH between 9.5 and 9.6. When a precipitated product that is soluble in the Drierite treated ether begins to evolve, additions of ammonia gas serve to raise the 3 alkalinity until, at optimum charge, pH 9.5 or 9.6 by test is reached. Separation is effected by decanting the ethereal layer. The precipitate is dried, preferably under vacuum, to achieve dry ammonium thioglycolate, with a self-com tained or in situ deposited base which may evidence a pH of 6.5 to as high as pH 10.5.

The ether employed in the foregoing and subseqently described examples is that which has been dehydrated as by Drieritc (a calcium sulfate dehydrating or like agent).

In carrying out this reaction, it is preferred to prepare a 200 ml. 0.39 molar solution of thioglycolic acid in butyl ether which is placed in a flash and then cooled with Dry Ice (40 C.). A second flask containing 175 ml. of ethyl ether was cooled to 40 C. by means of a Dry Ice bath; and, while so chilled, ammonia gas was introduced into and condensed in the ethyl ether until 34 grams of ammonia had been added. The chilled solution of thioglycolic acid was added by a dropping funnel to the ethyl ether-ammonia and a white precipitate formed. When the addition was complete, the flask containing the precipitate was removed from the Dry Ice and allowed to warm to room temperature. It wasthen stoppered and placed in a Dry Ice chest overnight and the next morning it was allowed to warm to room temperature. The precipitate was separated, washed with dry ethyl ether and dried in a vacuum desiccator. The X-ray difiraction pattern of the precipitate obtained by this process shows no evidence of crystallinity audit is an amorphous product. A 1.0 percent aqueous solution exhibits a pH of 9.0.

The dry preparation thus provided may have added to it from 2% to 5% of dry crystalline sodium hydrosulfite The dry in situ basic ammonium thioglycolate, with or without the sodium hydrosulfite, may be packaged in pill form in sealed foils, capsules or ampules, envelopes or packets, until ready for use, with little or no deterioration. Where high humidity conditions may be encountered, a moisture occluding coating may be applied to the pills similar to the enteric coatings found on some medicinal preparations. Normally solid sulphonated oils providing a material in the nature of a detergent may be employed ascoatings. If packaged in envelopes, the presence of the sodium hydrosulfite serves as a reducing agent for any oxidation product.

In use, grams of the solid may be added to 100 cc. of water. I prefer, for the benefits hereinbefore indicated, to use standard carbonated water, the beverage, or standardized carbonic acid solutions in which the demineralized water has been charged with carbonic acid to a pressure of five volumes of gas to one volume of water. This formula will be eflfective in from 10 to 40 minutes, depending upon the nature of the hair.

The procedure for cold waving may be to apply the freshly made solution in the carbonated water to the hair and when saturated upon curlers, in accordance with standard procedure such as Croquignole or spiral wire curlers recirculation, preferably a loose wind, the procedure varying in that the efiervescing solution may be applied directly to the hair without the necessity for preliminarily rinsing or washing the same. Inter-facial gaseous agitation between the layer of the solution and the hair makes possible the elimination of wetting agents as well as to cause the release of any adherent scale, dust and more intimately to bring the hair waving solution into contact with the hair. The hair may then be covered with additional quantities of the solution, such as by pads saturated with the solution, and the head is then desirably covered with some impervious cap such as by covering the entire head with a shower cap.

The hair may be left in this condition from thirty minutes to eight toten hours, depending upon the concentration which is employed. A adjustment of the base to the thioglycolate to provide pH about 9.5 to 9.6 and a concentration of the thioglycolate in water to about 8% has been found to result in a preparation which, with some types of hair, requires only a half hour contact for inducing the desired wave. Adjustments may be found necessary in the time and concentration as different types of hair are required to be treated, it being observed that the greater the concentration and pH, the lower the time factor and, conversely, the more dilute the solution and the lower the pH, the longer will be the time necessary to effect the desired wave. Therefore the amount of time for treatment will be a factor of concentration and pH.

The hair, after treatment and removal from the form which holds it curled, is rinsed with water. Preferably an acid shampoo or detergent is used, and benzyldirnethylammonium chloride (phemerol chloride) is suggested.

Example II.-For the preparation of a composite thioglycolate in situ mixed base, the dry preparation may be as follows:

Seven grams of sodium hydroxide are dissolved in 150 ml. of ethyl alcohol with stirring. A solution of 10 grams of vacuum distilled thioglycolic acid in 50 m1. of ethyl alcohol was added through a dropping funnel to the solution of sodium hydroxide with continued stirring of the thioglycolic acid solution. Simultaneously, ammonia gas is bubbled through the sodium hydroxide solution; and, during this gaseous infusion of ammonia and while the stirring was continued, the thioglycolic acid solution was introduced in small amounts extending over a period of 10 minutes. With each addition of the acid a heavy white precipitate formed that redissolved to form a cloudy solution. At the end of the addition of the acid a short period of time passed in which a cloudy solution existed and then a heavy granular precipitate formed. The precipitate .was separated by filtration, washed with ether and dried in a vacuum desiccator over calcium chloride. The product was a granular, free-flowing solid which, in a 1 percent aqueous solution (distilled water), gave a pH of 11.1.

The foregoing reaction is accelerated by carrying out the reaction under refrigerated or chilled conditions. That is, the ethyl alcohol solution of sodium hydroxide may be cooled to a temperature of about or below 10 C. and preferably, of from 0 to 5C.

The precipitated product may be dried and packaged or formed into a dry merchandizable product in accordance with the procedure heretofore described. This prod-' uct may be mixed with the crystalline sodium sulfite before packaging. Where the dry preparation is made, the procedure hereinbefore described for solution in a carbonated water should be followed.

Example III.--In this preparation, 10 grams thioglycolic acid, 3 grams monoethanolamine and 1 gram so dium thioglycolate are dissolved in isopropyl ether (Drierite treated) cooled to about 37 F.

Stoichiometric amounts of ammonia gas may be infused into the chilled solution, calculated to make a solution having a hydrogen ion concentration or pH 8.5 when a test sample is introduced into cc. water. The precipitated reaction product is dried to evaporate any residual ether. This compound may be hygroscopic and is preferably mixed with the reducer or clearing salt previously described in the same ratio and packaged in ampules. The ampule packaged dry material may be employed in the process heretofore described for permanently waving hair in the cold, employing the procedure before described, especially using carbonic acid charged water.

While I have described the preparation of a dry thioglycolate in which the base is the ammonia radical or a mixture of ammonia and alkali metal hydroxide such as sodium, 1 may prepare a dry preparation in which an organic salt of thioglycolic acid is produced. Accordingly, an organic base, such as guanidine, morpholine or ethylene diamine may be reacted with thioglycolic acidv to procure a thioglycolate which is normally dry and has essence or isopropanol. While the reaction mixture is chilled at a temperature below about 37 F. the reaction product s thrown out upon the addition of the organic base and is filtered and vacuum-dried, as previously described. The quantity of the base may be to retain the pH below 9.6 and as low as pH 7. The addition of the base in excess of an amount to produce pH 9.6 may require careful handling as to time and concentration as above pH 10.5 and as high as pH 13.0 may be secured to produce a depilatory if desired, with the proper control of time and concentration.

The organic addition salts of thioglycolic acid, such as the guanidine thioglycolate, the morpholine thioglycolate or the ethylene diamine salt, where employed, are more desirable than the ammonium and sodium thioglycolates in that as solutions they evidence practically no offensive odors and may be employed in solutions having a lower pH, i.e. pH 7.6, as compared with pH 9.5 for ammonium thioglycolate and in a concentration of one half strength, i.e. 2Vz% solution as compared with 6.9% solution of ammonium thioglycolate.

Example I V.--In this example 2 moles thioglycolic acid (184 grams) are treated with 1 mole guanidine carbonate (180 grams-equivalent to 2" moles of free guanidine base) in an ether solution.

The mixture is allowed to stand under refrigerated conditions C.) for two hours until the reaction salt which precipitates settles, whereupon it is filtered, dried, dissolved in water and recrystallized. The dried salt shows a melting point of IDS-106 C., with an assay of 99.8%.

The guanidine thioglycolate which is thus formed may be dissolved in water to form a 6.8% solution (based on thioglycolic acid content), and then mixed with a base of pH 7.6. A cold wave made with this solution provides a longer-lasting curl than sodium or ammonium thioglycolate solutions of equivalent strength having pH 9.5, in that the curl is tighter and persists upon drying, rather than showing a tendency ,to loosen upon drying.

While most of the mercaptan compounds of sodium and ammonia in alkaline media swell the hair fibres, making it appear grayish, frizzy and losing at least 25% of its original diameter of curl, the organic guanidine thioglycolate and base mixture, as here described, seems to contract thehair and give a curl that appears shiny, smooth and in effect at least 10% smaller in diameter than the original curl.

Example V.--l mole of guanidine'carbonate is added, with constant stirring, to a dry isopropyl ether solution maintained at a temperature of 5 C. and containing 2 moles of thioglycolic acid. A white coprecipitate insoluble product of guanidine thioglycolate forms in a menstrum of excess basic carbonate. This is filtered oil and dried. An aqueous layer consisting of guanidine thioglycolate and carbonate dissolved in the water of salt formation also is obtained. This is separated from the other layer, the water evaporated off under vacuum and the dry super based guanidine thioglycolate and base recovered from the water layer is mixed with the precipitate with added dry base to leave a dry product of predetermined alkalinity.

The aforesaid resulting guanidine thioglycolate and admixed carbonate may be packaged dry, as in the prior examples, to be used by solution in water to make a 3% concentration calculated as thioglycolic acid and pH 9.0.

The procedure for cold waving by dissolving in standardized carbonated water, as previously described, may be also followed with the organic salt of thioglycolic acid and base admixture. The dry curls made with this form of the thioglycolate mixture provides a tighter curl than ammonium and sodium thioglycolate, which has been alkalinized to pH 9.5 with a 6.1% of thioglycolic acid value in solution.

Example VI.2 moles of morpholine (174 grams) are added with constant stirring to 3 moles thioglycolic acid dissolved in isopropyl ether (dried as before described) and chilled to 0 C. r

A heavy, waxy precipitate is thrown out of solution. This precipitate is filtered, redissolved and recrystallized from water to provide a product having a melting point of 78 C., with an assay of 99.83%.

The dry super based morpholine thioglycolate and associated base may be dissolved in water which, when using 6.5% (calculated as thioglycolic acid), gives a solution having pH 9.5. This preparation gives a tighter curl, with more lustrous sheen than sodium or ammonium thioglycolate at the same pH and concentration.

Accordingly the dry product stripped from the ether mixed with or coprecipitated with the added base or morpholine to raise the pH within a range from 7.5 to 9.5 or above, may be packaged in accordance with any of the procedure, heretofore described and may be em- .bodied in a carbonated water as a solvent, with the features heretofore described for carrying out the hair waving treatment. The added base in dry form may exceed 9.5 where other than cold hair waving products are formed.

Example VII.l mole of 70% ethylene diamine is added to 2 moles thioglycolic acid. Isopropyl alcohol chilled to a temperature of 3 C. (37 F.) is added to show the formation of the organic salt of thioglycolic acid as a heavy precipitate. The salt is filtered and dried.

The thioglycolate is hygroscopic and does not give a sharp melting point. Analysis for the mercaptan value shows the material to be and corresponding to the following formula:

The thus formed ethylene diamine thioglycolate, which is separated, when formed in a solution of water in concentration of 5% calculated as thioglycolic acid and added base to give pH 8.8 may be employed to wave hair and gives a better cold waving curl than the corresponding salt of sodium, ammonium thioglycolate and the mixed sodium and ammonium thioglycolate of high strength and pH value.

Accordingly the ethylene diamine thioglycolate, either coprecipitated or dry mixed with a base to provide a dry product, may be packaged or pill formed as above after the dry mercaptan salt and base are brought together to the desired pH.

Example VIII.-l mole of thioglycolic acid is slowly added to 1 mole of 70% ethylene diamine. Equal volume of isopropyl alcohol is added and the mixture permitted to stand in a refrigerator at 37 F. overnight. The precipitate is separated and dried. The mercaptan analysis of the material showed an assay of 94.8% as ethylene diamine mono-thioglycolate.

A 6% concentration solution (on a thioglycolic acid basis) with added base to give pH 9.5 may be prepared in water.

A cold waving solution may be made in accordance with the procedure previously outlined, preferably employingthe carbonated water. The curl, upon drying, exhibits the properties heretofore described in connection with the previously described organic salts of thioglycolic accuses 'l by the addition of a base to pH from 11.9 to 12.2, with the said guanidine thioglycolate content of 6% based on the thioglycolic acid.

Example IX.--8.5 grams thiolactic acid are suspended in isopropyl ether chilled to a temperature of about C. to which monoethanolaminc is added in which a test sample shows pH 8. Thereupon ammonia gas is infused until a test sample shows pH 8.5.

The reaction forms an aqueous and ether layer which may be decanted. The resultant salt which precipitates of lactic acid is vacuum dried. The presence of the monoethanolamine in this particular case may make a hygroscopic mixture and the dry preparation is desirably maintained in ampules, to be used in one form of my invention with the carbonated water as previously described in applying the cold waving solution to the hair.

A further formula is as follows:

Example X .N-oxyethylthioglycolamide is made by dehydrating a mixture of monoethanolamine and thioglycolic acid. The mixture is heated at about 140 C., at a pressure of to 22 mm. until the proper computed amount of water is removed and collected. The resulting product is ready for immediate use.

Example Xl.lsopropanolamine substituted for the monoethanolamine under the same conditions as in Example X yields a corresponding product, similarly useful. The product is N-oxypropyldithioglycolamide.

Example XII.-As another method for making a dry, self-contained thioglycolamide preparation, the following procedure is outlined:

To 0.1 mole methyl thioglycolate (or 10 grams) in refrigerated (37 F.) isopropyl ether there are introduced 0.2 mole ammonia gas (or 121 grams of NI-hOI-I (28%)) until no more ester layer is visible. or it may be brought up by excess ammonia to give a thioglycolamide of about pH 9.9. Then reduce the pH with carbon dioxide gas to any pH desired, preferably pH 9.5, where a reduction in pH is to be accomplished. Where a higher pH is desired, more ammonia gas is introduced into the batch. Decant theisopropyl ether layer and dry the salt under vacuum. The resulting salt may then be packaged for use with the carbonated water, as previously described. The concentration in each charge or pill or package and its pH will be determined and instructions given in accordance with the time of treatment and hair to be waved.

Example XIII.60 ml. of ethyl thioglycolate was placed in a graduate and ml. of 70 percent alcohol was added. Dry ammonia gas was bubbled through the liquid, producing considerable turbulence. The addition of ammonia gas was continued for about l2 hours (overnight), and a syrupy, semi-solid product was formed that was readily soluble in water. Chilling the reaction mixture to 10 C. caused the product to congeal to a pasty mass. Cooling in a Dry Ice bath gave a hard solid mass which, when warmed to room temperature, became a waxy solid. This was dried under vacuum over calcium chloride and the product gave a pH of 6.9 in a 1 percent solution in distilled water.

It will be seen from the foregoing examples that either thioglycolic acid or an alkyl thioglycolate may be reacted with a base in an anhydrous liquid medium; such as, for example, lower alcohols and lower ethcrs. to provide unique new products which, when dissolved in water. provide hair waving solutions having a pH not less than 6.5. It is essential that the reactions for preparing these novel products be carried out under chilled or refrigerated conditions (37 F.) or at lower temperaturesfprcferably at 0 C. and as low as -4l C. The reaction proceeds slowly at temperatures above 0 C. and may take as long as from 12 to 24 hours to become completed. At temperatures of about 0 C. and lower (4l C.) or in the range of from -4l0" C., the reaction proceeds rapidly. In carrying out the reactions it is possible to maintain one or both reactants in sepu arate, chilled solutions which are mixed with agitation or the base, when in gaseous form. may be infused into a chilled solution of the thioglycolic acid or alkyl thioglycolate in the anhydrous organic liquid medium. It is also possible to introduce the reactants into the anhydrous liquid medium and then subject the reaction mixture to the above refrigerated or chilled condition to precipitate out the desired product.

The aforesaid dry powder, pill, capsulated or ampulated products in each of the examples are to be furnished to the trade to be used with neutralizer compounds furnished in dry form or with other known neu tralizer compounds. For purposes of exemplification I refer to sodium perborate. This perborate solution may have added to it immediately before use, after the hair treatment with the mercaptan compounds, solutions of acetic acid or vinegar, tartaric acid or malic acid, in order to produce a nascent hydrogen peroxide solution of acidified character.

Where a dry mercaptan is made by the formation of an amide of extreme basic nature, it may be brought to the lower pHs within the desired range and preferably about pH 9.5 or lower in the dry form by the addition of carbon dioxide gas.

Likewise, while I may reduce the pH of the basic thioglycolamide with carbon dioxide, I may do so by adding an acid mercaptan in order to reduce the pH in the foregoing formula of a ratio of .1 mole of methyl thioglycolate to .2 mole of ammonia, which will provide an ester which has about pH 9.9.

Other reaction products and mechanical inter mixtures will suggest themselves from my disclosure in my application Serial No. 437,628 with regard to the formation of a dry thioglycolate coprecipitated base and/or basic admixture for use in forming a self-contained in situ precipitated thioglycolate or mercapto radical and base which optionally. upon the addition of the sulfite or clearing salt heretofore described, may be stored dry as a powder, or in an ampule. Thus also the dry sodium thioglycolate as an acidic component below pH 7 may be coprecipitated or mixed with ammonium carbonate, or guanidonium carbonate to above pH 7.

These components or mixtures upon addition to charged or carbonated water in accordance with the standardized prescription for making the beverage, or in a water extended paste result in the desirable cold hair waving preparation heretofore described. The use of distilled water will give desirable results in each instance.

Likewise it will be understood that the aforesaid preparations may be employed to crease-proof woolens and like keratin containing products.

The solution may also be employed for embossing animal fibres.

Increase of the added base to give a product of as high as pH 13 makes the product valuable for depilation.

Likewise while I have described the preparation of the base-fortified dry mercaptan mixtures for usein pills, capsules, ampules, packets, a cream may be made of said preparations employing diglycol laurate-S. The dry mercaptan compound may be used as a 3.5%-l0% addition to the water extended paste-like laurate compound.

In general, the provision of the mercapto or thioglycolate salt, with either of the organic or inorganic bases, as herein described, assures predetermined strength and standardized reaction after storage of a hair waving preparation, and is particularly valuable where the preparation is dissolved in water charged with carbonic acid, as described, to provide a cold waving preparation in which the resulting curl persists from the wet to and including the fully dried condition without loss of curl curvature.

The utility of the product may be outlined as satisfactory not only for curling hair but likewise for straightening hair. Also it may be used to crease proof fabrics made of wool or to impart a permanent crease to articlcs of apparel, such as pleating, embossing fabrics either abscess in the hot or cold, and likewise to soften hair and taire away its harshness or brittleness. It may be used to soften nails or cuticles and also to modify or permanentize the pile condition of fur, either to flatten or raise it. Likewise'the wide range of conditions which may be emphasized will be clear in that I may treat Chinese hair or horse hair, i.e. the tail and mane hairs as well as to soften and curl dog hair for example poodle, and related uses in the veterinarian field.

I also consider forms of my invention as providing a normally dry mercaptan compound which may be in the acid form, in which event a quantity of base is added to bring it to the upper required pH or, conversely, a dry basic mercaptan may be reduced with a charge of carbon dioxide to a range to pH 7.

In emphasizing the merit of the dry preparation, it should be borne in mind that in making aqueous solutions for the trade, it has been found necessary to allow extra strength for deterioration by reason of oxidation of mercaptan and evaporation of ammonia since this occurs either on the shelf or after the user has opened up the bottle for partial use. In that manner, instructions for use cannot be uniformly followed whereas in accordance with my invention, the dry preparation being consumed immediately upon dilution, a predetermined concentration and strength will. dictate uniform instructions for use.

As a further distinguishing feature of my invention, it is to be noted that it has been the practice to supply the trade with a greater concentration of the mercaptan compound in order to allow for deterioration, with the result that when the fresh product is used it may have a delete rious etfect on the hair.

In the foregoing disclosure where I have specified the use of carbonated water and more particularly carbonated beverages as the materials which are to be employed for dissolving'the drymercaptan compounds, it has been found that the beverages existing on the market with a calcium content of about 8.0 parts per million and a magnesium content of 1.5 parts per million are representative of the type of carbonated beverages which may be used in accordance with my invention. The objective to be observed is to as much as possible the use of an aqueous solute such as hard'water which carries into the hair an excessive amount of 'lime or magnesium which, during the concentration which occurs in leaving the preparation on the hair, may have a deleterious etfect on the hair.

l-claim:

1. A stable dry composition for imparting wave to human hair when dissolved in water and containing as its essential active ingredient a dry, precipitated, solid, granular reaction product of a compound selected from the group consisting of thioglycolic acid and an alkyl thioglycolate and a'base selected from the group consisting of ammonia, an amine, guanidine'and morpholine, said reaction product being precipitated in a chilled anhydrous organic liquid medium selected from the group consisting of lower alcohols and ethers maintained by said base at a pH in the range of 65-10 as determined whena test sample is introduced into 100 cc. of water, said base being in an amount in excess of the stoichiometric amount based on the amount of said compound, said reaction product providing, upon dissolution in Water, a hair waving solution having a pH not less than 6.5.

2. The product of claim 1 wherein said dry composition is in the form of free-flowing granules.

3. The product of claim 1 wherein said dry composition is in the form of a compressed tablet body.

'4. The product of claim 3 wherein said compressed tablet body is provided with a coating of a solid detergent composition.

5. A stable dry composition for imparting wave to human hair when dissolved in water and containing as its essential active ingredient a dry, precipitated, solid granuid lar reaction product of a compound selected from the group consisting of thioglycolic acid and an alkyl thioglycolate, and a base selected from the group consisting of ammonia, an amine, guanidine and morpholine, said reaction product having been precipitated in an anhydrous organic liquid medium selected from the group consisting of lower alcohols and ethers chilled at a temperature not 6. The product of claim 5 wherein said reaction prodact is precipitated in said anhydrousorganic liquid medi um at a temperature in the range of from 41 C. to about 0' C.

7. The method of preparing a stable, dry, precipitated, solid granular reaction product which, upon dissolution in water provides a hair waving solution, comprising dissolving a compound selected from the group consisting of thioglycolic acid and an alkyl thioglycolate and a base selected from the group consisting of ammonia, an amine, guanidine and morpholinc, said reaction product being precipitated in an anhydrous organic liquid medium selected from the group consisting of lower alcohols and ethers chilled to a temperature not in excess of 37 F., said base being in excess of the stoichiomet-ric amount based upon the amount of said compound and said anhydrous organic liquid medium being maintained by said base at a pH in the range of 6.5-10 as determined when a test sample is introduced into cc. of water, to precipitate a reaction product in a solid granular form; and recovering said reaction product from said anhydrous organic liquidmedium.

8. In a method of imparting" a permanent wave to human hair including the steps of. forming human hair into a desired configuration, applying an aqueous solution of a hair-softening agent tosaid formed hair and fixing the configuration, the improvement which consists of providing said hair-softening agent by dissolving the composition of claim 5 in water having a calcium content less than about 8.0 parts-per million and .a magnesium content less than 1.5 parts per million. 1

9. The process of'claim 8 wherein the hair is neutralized by the application of a neutralizing agent after the configuration of the hair has been fixed by application of the hair softening agent.

References Cited inthe file of this patent UNITED STATES PATENTS 455,102 Hubener June 30, 1891 1,160,317 Perine Nov. 16, 1915 1,616,202 Shook Feb. 1, 1927 1,987,526 Elbel et al. Ian. 8, 1935 2,183,894 Pye Dec. 19, 1939 2,222,830 Moss -2 Nov. 26, 1940 2,331,065 Willat -2 Oct. 5, 1943 2,389,755 Baker Nov. 27, 1945 2,412,282 Nelson Dec. 10, 1946 2,418,664 Ramsey Apr. 8, 1947 2,465,346 Bodman Mar. 29, 1949 2,477,492 Moose July 26, 1949 2,506,492 De Mytt May 2, 1950 2,594,030 Coons et al. Apr. 22, 1952 2,600,624 Del Zoppo June 17, 1952 2,631,965 Schnell Mar. 17, 1953 2,660,568 Cunder Nov. 24, 1953 (Other references on following page) aeeeese 11 FOREIGN PATENTS Great Britain Juiy 16, 1952 France Feb. 13, 1951 Great Britain Ian. 30, 1939 Germany Jan. 22, 1906 France Nov. 21, 1951 OTHER REFERENCES Beilstein: Handbnch der Org. Chem, 4111 ed., 1921 vol. 3, pp. 245, 257, 258.

Patent ent requiring corr corrected below.

UNITED STATE 5- PATENT. OFFICE Harry Martin is hereby TIFICATE r acrroN June 27, 1961 certified that error appears in the above numbered petection and that the said Letters Patent should read as Column 1 line 18, for "Patent No. 2,773,293" read abandoned I Signed and sealed this 6th day of March 1962.

(SEAL) Attest:

ERNEST W. SWIDER Attesting Officer DAVID L. LADD Commissioner of Patents 

1. A STABLE DRY COMPOSITION FOR IMPARTING WAVE TO HUMAN HAIR WHEN DISSOLVED IN WATER AND CONTAINING AS ITS ESSENTIAL ACTIVE INGREDIENT A DRY, PRECIPITATED, SOLID, GRANULAR REACTION PRODUCT OF A COMPOUND SELECTED FROM THE GROUP CONSISTING OF THIOGLYCOLIC ACID AND AN ALKYL THIOGLYCOLATE AND A BASE SELECTED FROM THE GROUP CONSISTING OF AMMONIA, AN AMINE, GUANIDINE AND MORPHOLINE, SAID REACTION PRODUCT BEING PRECIPITATED IN A CHILLED ANHYDROUS ORGANIC LIQUID MEDIUM SELECTED FROM THE GROUP CONSISTING OF LOWER ALCOHOLS AND ETHERS MAINTAINED BY SAID BASE AT A PH IN THE RANGE OF 6.5-10 AS DETERMINED WHEN A TEST SAMPLE IS INTRODUCED INTO 100 CC. OF WATER, SAID BASE BEING IN AN AMOUNT IN EXCESS OF THE STOICHIOMETRIC AMOUNT BASED ON THE AMOUNT OF SAID COMPOUND, SAID REACTION PRODUCT PROVIDING, UPON DISSOLUTION IN WATER, A HAIR WAVING SOLUTION HAVING A PH NOT LESS THAN 6.5. 